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A093803 Greatest odd proper divisor of n; a(1)=1. 2
1, 1, 1, 1, 1, 3, 1, 1, 3, 5, 1, 3, 1, 7, 5, 1, 1, 9, 1, 5, 7, 11, 1, 3, 5, 13, 9, 7, 1, 15, 1, 1, 11, 17, 7, 9, 1, 19, 13, 5, 1, 21, 1, 11, 15, 23, 1, 3, 7, 25, 17, 13, 1, 27, 11, 7, 19, 29, 1, 15, 1, 31, 21, 1, 13, 33, 1, 17, 23, 35, 1, 9, 1, 37, 25, 19, 11, 39, 1, 5, 27, 41, 1, 21, 17 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,6

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..10000

FORMULA

a(n) <= A000265(n);

a(n) = n / (A020639(n)*(n mod 2) + A006519(n)*(1 - n mod 2)).

a(n) = A000265(A032742(n)). - Antti Karttunen, Aug 12 2017

MAPLE

with(numtheory): a := n -> max(1, op(select(k->type(k, odd), divisors(n) minus {n}))): seq(a(n), n=1..85); # Peter Luschny, Feb 02 2015

MATHEMATICA

Join[{1}, Table[Max[Select[Most[Divisors[n]], OddQ]], {n, 2, 90}]] (* Harvey P. Dale, Apr 10 2012 *)

PROG

(Scheme) (define (A093803 n) (/ n (if (odd? n) (A020639 n) (A006519 n)))) ;; Antti Karttunen, Aug 12 2017

CROSSREFS

Cf. A000265, A005408, A006519, A006530, A020639, A032742, A078701.

Sequence in context: A077308 A075001 A252840 * A285175 A016599 A079650

Adjacent sequences:  A093800 A093801 A093802 * A093804 A093805 A093806

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, May 19 2004

STATUS

approved

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Last modified March 2 06:37 EST 2021. Contains 341744 sequences. (Running on oeis4.)